The hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) are rodent-borne zoonoses caused by certain members of the virus family Bunyaviridae, genus Hantavirus. Specific rodents (i.e., one or two closely related members of the order Rodentia) are the principal hosts of the hantaviruses known to cause human disease. The reverse transcription-PCR (RT-PCR) assays have been employed extensively to detect hantaviral RNA in clinical samples from HPS and HFRS patients and to obtain amplified products for viral characterization by DNA sequencing. Hantaviruses usually are extremely difficult to isolate from clinical materials. Thus, virus isolation is not commonly used for the diagnosis of hantaviral infections in humans. Neutralization of infectivity in vitro, immunofluorescent-antibody assays (IFAs), enzyme-linked immunosorbent assays (ELISAs), and a host of other serologic methods have been used to characterize hantaviruses isolated from clinical samples and rodents. The use of genetic sequence data to define taxonomic relationships within the genus Hantavirus has become increasingly important, in part because some hantaviruses have never been adapted to growth in cultured cells and because our knowledge of the serologic relationships among some of the hantaviral species is based on one strain per species. Early diagnosis is critical to the successful management of HFRS and HPS and, at least in the case of HPS caused by Andes virus, implementation of appropriate isolation procedures to prevent virus transmission to health care providers and other people.

Electron micrograph of negatively stained Sin Nombre virus (2% phosphotungstic acid stain, pH 6.5). Courtesy of Charles Humphrey, Centers for Disease Control and Prevention. Humans usually become infected with hantaviruses by inhalation of aerosolized droplets of urine, saliva, or respiratory secretions from infected rodents or inhalation of aerosolized particles of feces, dust, or other organic matter contaminated with secretions or excretions from infected rodents. The aerosol transmission of hantaviruses from rodents to humans has been well documented (49, 110). Other means of infection include contamination of cutaneous injuries with infectious virus, contact of infectious materials with mucous membranes, ingestion of food contaminated with infectious rodent secretions or excretions, laboratory-acquired infections (7, 49, 58, 63, 118), and—only in the case of Andes virus—contact with an HPS patient during the acute phase of illness (84). Note that person-to-person hantavirus transmission has never been documented in Europe, Asia, or North America.

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FIGURE 1

Electron micrograph of negatively stained Sin Nombre virus (2% phosphotungstic acid stain, pH 6.5). Courtesy of Charles Humphrey, Centers for Disease Control and Prevention. Humans usually become infected with hantaviruses by inhalation of aerosolized droplets of urine, saliva, or respiratory secretions from infected rodents or inhalation of aerosolized particles of feces, dust, or other organic matter contaminated with secretions or excretions from infected rodents. The aerosol transmission of hantaviruses from rodents to humans has been well documented (49, 110). Other means of infection include contamination of cutaneous injuries with infectious virus, contact of infectious materials with mucous membranes, ingestion of food contaminated with infectious rodent secretions or excretions, laboratory-acquired infections (7, 49, 58, 63, 118), and—only in the case of Andes virus—contact with an HPS patient during the acute phase of illness (84). Note that person-to-person hantavirus transmission has never been documented in Europe, Asia, or North America.

Photomicrograph of human lung tissue showing hantaviral antigens in pulmonary microvasculature by using immunohistochemistry. Viral antigens are stained in red. Courtesy of Sherif Zaki, Centers for Disease Control and Prevention.

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FIGURE 2

Photomicrograph of human lung tissue showing hantaviral antigens in pulmonary microvasculature by using immunohistochemistry. Viral antigens are stained in red. Courtesy of Sherif Zaki, Centers for Disease Control and Prevention.

113.Van Loock, F.,, I.Thomas,, J.Clement,, S.Ghoos,, and P.Colson. 1999. A case-control study after a hantavirus infection outbreak in the south of Belgium: who is at risk?Clin. Infect. Dis.28:834–839.

a Adapted from references 54, 79, 91, 93, and 124. Amur virus has been associated with HFRS in eastern Russia; Apodemus peninsulae is the natural host. Additional hantaviruses associated with HPS include Monongahela virus in the United States; Central Plata virus in Uruguay; Choclo virus in Panama; Bermejo, Lechiguanas, and Oran viruses in Argentina; and Anajatuba, Araraquara, Castelo dos Sonhos, and Juquitiba viruses in Brazil. Monongahela virus is a strain of Sin Nombre virus, and Bermejo, Lechiguanas, and Oran viruses are considered strains of Andes virus. Sigmodontine rodents are the natural hosts of Anajatuba, Araraquara, Bermejo, Central Plata, Choclo, Juquitiba, Lechiguanas, and Oran viruses. The natural host of Castelo dos Sonhos virus is not known.

b Murinae, Old World rats and mice; Arvicolinae, voles and lemmings; Sigmodontinae and Neotominae, New World rats and mice.

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TABLE 1

Hantaviral species associated with human diseasea

a Adapted from references 54, 79, 91, 93, and 124. Amur virus has been associated with HFRS in eastern Russia; Apodemus peninsulae is the natural host. Additional hantaviruses associated with HPS include Monongahela virus in the United States; Central Plata virus in Uruguay; Choclo virus in Panama; Bermejo, Lechiguanas, and Oran viruses in Argentina; and Anajatuba, Araraquara, Castelo dos Sonhos, and Juquitiba viruses in Brazil. Monongahela virus is a strain of Sin Nombre virus, and Bermejo, Lechiguanas, and Oran viruses are considered strains of Andes virus. Sigmodontine rodents are the natural hosts of Anajatuba, Araraquara, Bermejo, Central Plata, Choclo, Juquitiba, Lechiguanas, and Oran viruses. The natural host of Castelo dos Sonhos virus is not known.

b Murinae, Old World rats and mice; Arvicolinae, voles and lemmings; Sigmodontinae and Neotominae, New World rats and mice.